Which Statement Is Not True About Checkpoints in the Cell

Multiple Choice

Which statement is not true about checkpoints in the cell cycle?

A) They can halt cell cycle progression in response to environmental influences.
B) They are a complex machinery that uses cyclins and cyclin-dependent kinases to regulate cell cycling.
C) They occur only in the middle of the G? phase of the cell cycle.
D) All of these are correct.
E) None of these are correct.